Lightning!(:

What is it?


Lightning is a natural occurrence that is caused when electricity is discharged between clouds and the earth, or between two or more rain clouds. Lightning is known as a natural disaster when it strikes the earth and causes destruction to mankind, living things, and buildings.

History . .


The discovery of lightning was made, as we all know, by Benjamin Franklin during the second half of the eighteenth century. Franklin's original idea for his experiment was to stand on an electrical stand and hold an iron rod with one hand, so that a

LIGHTNING!!.jpg

n electrical discharge between his free hand and the ground would be created. According to Benjamin's theory, an electrically charged cloud could create sparks that would "jump" between the a grounded wire and the iron rod. Unfortunately, Franklin never successfully completed this experiment. He later changed the experiment slightly after two scientists attempted the experiment and died. Franklin finally succeeded in his experiment with electricity by using a kite and a key. That marked the beginning of electricity.





Into Depth. .



Lightning is known to be frightening and powerful, but really, what is it? Inside clouds, there are small particles known as"hydrometers". These particles interact as they grow, and the collisions cause them to become charged. Researchers have come to believe that the smaller particles are more positively charged and the larger particles negative.Gravity tugs and pulls the larger, negative particles downward and pulls the small, positive particles upward. This then causes the top portion of the cloud to have a net positive charge and the bottom portion a net negative charge.The separation of particles causes an electrical potential not only within the cloud, but within the cloud and the earth. Eventually, the electrical resistance in the air breaks down and lightning is formed.




The Most Common Types ..



*Cloud-to-ground lightning is definitely by far the most dangerous form of lightning, and even though this form isn't the most common form of lightning, it is the easiest to research. Most cloud-to-ground strikes begin near the lower part of the cloud. Since the cloud is negative charged, the strikes are most likely to have a negative charge as well. There is a small percentage chance, however, that the charge will be positive.
*Intra-cloud lightning is the most common form of lightning by far. This type of lightning occurs between two opposing charged portions of the same cloud. When this lightning strikes, an observer on the ground will not be able to see the flash of light. This is because the cloud obscures the lightning flash and therefore makes it hard to see.
*Inter-cloud lightning is very similar to intra-cloud lightning. The only difference between the two is that with inter-cloud lightning, the charges come from two separate clouds instead of being within the same cloud.


Dry Lightning. .



Another form of lightning that is not widely known about is dry lightning. Dry lightning is probably the most dangerous type of lightning. This is because there is no rain accompanying the lightning. Therefore, when it strikes, and any small sparks or fires that it may cause, have no rain to instantly put the fires out. The air and ground are warm and dry, so the fires spread quickly. Dry lightning is actually a major cause of wildfires in the dry western United States. Since the cumulonimbus clouds are more than 10 miles away in this case, the lightning is the only part of the storm heard. This dangers people because since the actual storm is not visible, they see no danger in being outside during it. They do not realize the danger in heat lightning, and how much harm it can cause.



Heat Lightning. .



Heat lightning is a form of lightning that sometimes confuses people because thunder is not necessary for it. These flashes are visible, even through no thunder sounds to accompany them. Heat lightning is a very common form of lightning that is sometimes not even noticed by the human eye because it sometimes does not interact with storms. In this case, the storm is occurring somewhere, but it is too far away to be seen or heard.

Heat lightning is also a factor when there are sudden temperature increases in the atmosphere. When cold temperatures suddenly turn warm, the different air pressures battle in the sky, and therefore heat lightning is produced.






lightning.gif
This is a drawing that explains how lightning is produced within the atmosphere. The positive charges and negative charges in clouds interact, and therefore, lightning forms.



Damages. .



Although it is hard to estimate the amount of damage created by lightning strikes because it is unpredictable, it is estimated that every year $4-5 billion worth of damage occurs. Lightning strikes are sometimes underestimated in that people don't expect severe damage from it. Therefore, children do not realize the risk they are taking when they play outside in thunderstorms. When the rare occasion happens and someone is struck by lightning, they face death or severe injuries. In the past thirty years, an average of thirty-eight people have been killed by lightning.

Buildings, towers, roads, wildlife, and the whole outdoors is constantly in danger of being struck. When something is struck, the damage can be severe, and this is where all of the money is needed to repair.
external image moz-screenshot.pngexternal image moz-screenshot-1.pngexternal image moz-screenshot-2.png

Did you know?. .



*About one hundred lightning bolts strike Earth's surface every second.
*Each single bolt can contain up to one billion volts of electricity.
*The risk for every person of being struck by lightning is 1:28,500.
*The heat of lightning can be up to FIVE times the heat of the sun.
*Lightning actually has a good part to it; it creates many nitrogen compounds that enable plant growth.




external image moz-screenshot-1.png

Sources. .


http://www.nssl.noaa.gov/primer/lightning/ltg_damage.html
lightning_strikes_map.gif
This map shows how many times lightning approximately strikes the United States.


http://thunder.msfc.nasa.gov/primer


http://www.public.asu.edu/~gbadams/lightning/lightning.html


http://www.usatoday.com/weather/resources/askjack/walightn.htm